STEER: 3D Printed Guide for Nerve Regrowth Control and Neural Interface in Non-Human Primate Model

Area of Science:

• Biomedical Engineering
• Neuroscience
• Materials Science

Background:

• Stable integration of synthetic materials with neural tissue is crucial for successful neuro-prosthetic applications.
• Reactive fibrosis is a major challenge limiting the long-term functionality of peripheral neural interfaces (PNIs).

Purpose of the Study:

• To fabricate and evaluate a novel PNI designed to harness fibro-axonal outgrowth and incorporate fibrosis for enhanced stability.
• To test a proof-of-concept PNI that aims to overcome the limitations of reactive fibrosis in neural interfaces.

Main Methods:

• Two non-human primates were implanted with Substrate-guided, Tissue-Electrode Encapsulation and Integration (STEER) PNIs.
• A 3D printed guide was used to direct nerve regrowth for electrode encapsulation within fibro-axonal tissue.
• Electrophysiological measurements and morphological analysis were conducted after four months.

Main Results:

• A highly structured fibro-axonal composite formed within the STEER PNI.
• Successful conduction of action potentials across the neural interface was recorded.
• Immunohistology revealed myelinated axons encasing the implant in organized laminae.

Conclusions:

• The STEER PNI effectively reconfigured fibro-axonal tissue structure, ensuring long-term functionality and stability.
• The study demonstrates the feasibility of creating stable PNIs with long-term electrophysiological performance using a simple design.